1. Field of The Invention
The present invention relates generally to a power slider. Particularly, the present invention relates to a power seat slide device for automotive vehicle seats.
2. Description of The Prior Art
Conventionally, power seat sliders are known in the which comprise a rail arrangement wherein one rail is mounted on a vehicle body and a second rail is engaged with the mounted rail to as to be relatively movable thereto, a seat being mounted on the movable rail. An electric motor is connected so as to drive the movable rail for moving the seat in forward and rearward directions.
Such a conventional power seat slider is shown in FIG. 6. According to this arrangement, a gear box 2 transmits torque from -an electric motor 5 to a screw member 6. The gear box is attached via brackets 3, 3 to an upper inside surface 1a of an upper, slidable rail 1 by a pair of bolts 4. The motor 5 is attached, by screws, bolts, or the like, to an outer wall 1b of the slidable rail 1 such that an output shaft 5a of the motor 5 engages and input shaft 2a of the gearbox 2 for allowing rotation to be transmuted therebetween.
However, according to the above described construction, it is necessary to assure correct alignment between the output shaft 5a of the motor 5 and the input shaft 2a of the gearbox 2, but, since the only means for positioning the gearbox is via the brackets 3 and the bolts 4, if machining errors or the like cause positioning inaccuracies to occur in production correct alignment between these components cannot be reliably assured. Thus, the input shaft 2a and the output shaft 5a may become eccentric relative to each other and excessive load is thereby applied to the motor 5 and operability and durability of the drive assembly is considerably degraded and further, unacceptably noisy operation of the slider may result.
Moreover, during the assembly process, in which the gearbox 2 is positioned between the brackets 3, 3, to be fastened to the slidable rail surface la via the bolts 4, positional displacement of the gearbox may easily occur and assembly thus becomes troublesome and time consuming and costs and complexity are increased.